That Bixolon is a tricky printer(fiscal), I just finish an implementation for panama with that printer using a chrome app for easily receive print commands and enable to run it on any environment without having to set a public IP address in order to use it with hw_escpos and hw_proxy. This solution is for work with the printer with Odoo in the cloud and it's based on https://github.com/csrocha/fpoc-chrome. Until now I'm using an utility from TFHKA because I don't have the command and protocols manual. I test it already on google chrome/chromium under Ubuntu and Raspbian (on Rasperry PI 2).